44 research outputs found
Chiral Shock Waves
We study the shock waves in relativistic chiral matter. We argue that the
conventional Rankine-Hugoinot relations are modified due to the presence of
chiral transport phenomena. We show that the entropy discontinuity in a weak
shock wave is quadratic in the pressure discontinuity when the effect of chiral
transport becomes sufficiently large. We also show that rarefaction shock
waves, which do not exist in usual nonchiral fluids, can appear in chiral
matter. The direction of shock wave propagation in a vorticity is found to be
completely determined by the direction of the vorticity and the chirality of
fermions. These features are exemplified by shock propagation in dense neutrino
matter in the hydrodynamic regime.Comment: 5 pages; v3: published versio
Chiral Anomalous Dispersion
The linearized Einstein equation describing graviton propagation through a
chiral medium appears to be helicity dependent. We analyze features of the
corresponding spectrum in a collision-less regime above a flat background. In
the long wave-length limit, circularly polarized metric perturbations travel
with a helicity dependent group velocity that can turn negative giving rise to
a new type of an anomalous dispersion. We further show that this chiral
anomalous dispersion is a general feature of polarized modes propagating
through chiral plasmas extending our result to the electromagnetic sector.Comment: 13 pages
Chiral fermions on lattice axion strings
I discretize axion string configuration coupled to a Dirac fermion, which in
the continuum binds a massless chiral fermion in its core when the winding is
one. I show that such a configuration can host one or more chiral fermions when
regulated on the lattice. Realization of these chiral fermions relies on the
presence of Wilson-like terms similar to the Wilson term used in lattice domain
wall fermions. The number of chiral fermions on the string jumps as the
Wilson-like parameter is varied with respect to the other mass scales in the
problem. These jumps coincide with phase transitions along a two dimensional
surface passing through the string's core. A one-loop Feynman diagram is used
to demonstrate how anomaly inflow works in this lattice regularized theory.Comment: Typo corrected, new references added and style files change